Prepare a medium-hot fire in a charcoal grill and preheat an oven to 375°F.

Prick the eggplant with a fork in several places and place on the grill rack 4 to 5 inches from the fire. Grill, turning frequently, until the skin blackens and blisters and the flesh just begins to feel soft, 10 to 15 minutes. Alternatively, put under broiler until skin blackens.

Transfer to a baking sheet and bake until very soft, 15 to 20 minutes. Remove from the oven, let cool slightly, and peel off and discard the skin.

Place the eggplant flesh in a bowl and mash with a fork to a paste.

Add the tahini, garlic, the lemon juice and the cumin and mix well. Season with salt, then taste and add more tahini and/or lemon juice, if needed.

Transfer the mixture to a serving bowl and spread with the back of a spoon to form a shallow well. Drizzle the olive oil over the top and sprinkle with the parsley and olives. Serve at room temperature with pita chips.